Author(s): Hongyanli; Shanshan Bao; Yunqing Xuan
Linked Author(s):
Keywords: Chaos Theory; Delay Time; Embedding Dimension; Phase Space Reconstruction
Abstract: This study performed a rationality analysis of the delay time and embedding dimension value during phase space reconstruction in hydrological series and the effect on their chaotic characteristics. Using a monthly average runoff time series from the Ayanqian station (upstream) and the Jiangqiao station (midstream) in the Nen River Basin, we reached the following regularity conclusions. (1) Based on the flood season (4 months) in the Nen River Basin, we can deduce that the correlation sequence length for the runoff is 4～5 months, i. e., the delay time=3 or 4 is a reasonable choice. (2) Learn from the predictability experiment results for the monthly rainfall time series, we know that the calculation results of the G-P algorithm for the dimension of runoff series for the Nen River Basin are reasonable, i. e., the embedding dimension is no more than seven. (3) the most suitable parameters for the phase space reconstruction and its chaotic characteristic index in the Nen River Basin are as follows: delay time=3～4, embedding dimension=6～7, correlation dimension=2.90～3.00, maximum Lyapunov index=0.24～0.32, and the forecast time is 3～4months.
Year: 2018